Type 4 1800 (refresh) advice required.

Discussion in 'Mech Tech' started by grandmst, Mar 27, 2021.

  1. Hi all,

    Starting a thread because I'm not the best with engines and really would like some forum advice / guidance on what's the best to do and way to do it.

    Apologies now I will be asking loads of questions.

    Issues...
    Leaking pushrods
    Leaking what it looks like from nearside barrel close to the block.
    Leaking from center of flywheel / bolts, oil on backside of clutch.


    I'm thinking the barrel could be due to heads needing a re-torque possibly.

    Pushrods I believe the little sealant has perished so need fresh ones / cleaning and re installing (easiest of the jobs).

    Flywheel I'm not sure where to proceed it's a oil seal that's not even two years old.

    Happy for all advice what order to start.

    The above is my initial investigation, I think i might strip it down to see where all the oil is lying / coming from then go from there.
    [​IMG][​IMG][​IMG][​IMG]

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  2. 77 Westy

    77 Westy Supporter

    I doubt it, if it leaks retorquing probably won’t stop it, but worth checking anyway. If they’re aftermarket cylinders some have very large scallops for the studs and a very narrow sealing face.
    Make sure there are no grooves or burrs in the heads and case or tubes, cleanliness is essential, and no sealant. A smear of oil or O-lube is all that is necessary.
    Check the condition of the flywheel nose, and you did fit the O-ring? And get rid of all that sealant, just a smear on the split line if you must.
     
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  3. mikedjames

    mikedjames Supporter

    Check the oil make sure its engine oil in the bell housing, if its gearbox oil that will be the gearbox input seal.

    Your engine seal sort of looks a bit clean for an oil leak. You would expect to see a trace of oil dribbling down the engine block.

    It looks more like its coming out of the centre bolts, more like the flywheel is not sitting close to the crank for some reason - is the needle bearing holding the flywheel apart from the crank ? .
    How juddery is your clutch ? .
     
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  4. Clutch was no issue when driving smooth as butter.

    When taking apart the clutch facing the flywheel is well and truly oil soaked.

    I might do the gearbox input seal anyways while it is out
     
    Last edited: Mar 27, 2021
  5. In regards to heads they are marked with AMC. [​IMG]

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  6. 77 Westy

    77 Westy Supporter

    AMC heads are okay, although they possibly have smaller valves than the original VW 1800 heads.
     
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  7. MorkC68

    MorkC68 Administrator

    AMC do supply the 1800 spec heads, as you say they are okay, I found the quality good and ours are doing well after five years.

    Just don’t tell the samba boys you think AMC are okay, it will trigger all sorts of debates :D
     
  8. I will reply back to you multiple quote comment when on the pc later

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  9. So compression test is as follows.

    1 / 2 / 4: 100psi
    3 95psi

    according to ratwell. https://ratwell.com/technical/FAQ/FAQContent.html
    • 1800/2000cc: 85-135psi, no lower than 71 psi

    also took a video of the leak:
    apologies for next doors child.

    .


    Looks like it has been leaking from the distributor for a while then being pushed backwards towards cylinder 3.

    my initial thoughts are clean it up and sort the pushrod seals and flywheel, but happy to take any advice if i should dig further regarding the PSI.
     
  10. 77 Westy

    77 Westy Supporter

    I haven’t looked closely Mark but I’m fairly sure 1800 AMC heads come with 39mm inlet and 33mm exhaust valves. VW 1800 ‘S’ heads have 41mm inlet, 34mm exhaust. And I did say they were 'okay'. Especially for the price. And I seldom post on the samba, I'm far too sensitive.:D
     
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  11. 77 Westy

    77 Westy Supporter

    All the compressions are low, especially #3. But if the engine has been rebuilt with AMC heads, head gaskets and cylinder base shims the static CR will be low.
    What you do now depends on what you want to do. The engine will run with lowish compression so you could just sort out the oil leaks, or only the gearbox and flywheel seals if you can live with a few oil drips. I suppose the clutch is contaminated so you’ll need at least a new friction plate and you might as well fit a new starter motor bush too.
     
    Last edited: Mar 28, 2021
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  12. So with these heads I now know why I have always thought the van to be slow compared to other 1800's

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  13. 77 Westy

    77 Westy Supporter

    I’m just guessing what might have happened from the lowish compression. But there are many reasons why the engine might have poor performance. I’m assuming (and I know what that means) that you didn’t rebuild the engine, so you don’t know how it has been rebuilt?
     
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  14. To be fair it's a very old (the engine shop) unit I believe must be over 5 years old now easily..

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  15. Zed

    Zed Gradually getting grumpier

    If you do find a groove in your flywheel I managed to fit a slightly different size (depth) seal to mine moving the seal almost 2mm away from the wear and it worked. Don't throw the seal away, you may need to do some measuring and calculating. There are some vendors of seals with technical drawings that will show exactly what depth on say a 12mm seal, that the actual seal rides. Don't think a double seal one will work, it will not help - do the calculations, it's worth the brain ache. :thumbsup:
     
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  16. Cylinder 1 also seems leaky round the studs.

    I think first sensible thing is heads off and measure.

    I have never really been happy with the performance,

    If the heads if are what people say would the stock larger valves make enough difference in performance that I should source a decent set? [​IMG][​IMG][​IMG]

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  17. Zed

    Zed Gradually getting grumpier

    The oil has blown onto the studs.
    Yeah! take the heads off, calculate the CR. :thumbsup:
    No, the smaller valves are better for your bus at that cc. The big valve were for cars. People like them for making bigger cc bus engines.
     
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  18. MorkC68

    MorkC68 Administrator

    The ones I mentioned are the 41 x 34 valve heads, I priced them up on AA last year (and also on Ahnendorp) when I was thinking of rebuilding the 2.0 type 4 I had.

    I like thesamba, you know where you stand!! :D
     
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  19. I think you are 100% right here when I put the new seal in two years ago I don't remember replacing the o ring, it's very worn.

    I'm quite sure that's the reason for my flywheel leak.


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  20. 77 Westy

    77 Westy Supporter

    I can only find AA Porsche 42 x 36 but they don’t state the valve size in the 1.8l Type 4 heads. The 1800 AMC heads aircooled.net sells are 39 or 39.3 x 33.

    There is loads of really good info on the samba, but I don’t always agree and I can’t be bothered to argue with ones that think they are always right.
     
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